Integrally moulded plastic plug ring cap

ABSTRACT

A screw cap produced by a bi-injection moulding process is disclosed herein in which discrete thermoplastics are moulded sequentially for resulting correspondingly into a soft inner lip and outer hard shell for sealing containers or conduits having an externally threaded neck, said containers or conduits being directed at holding or conveying chemical, food, and pharmaceutical preparations.

FIELD OF THE INVENTION

This invention relates generally to articles made of formable materials. More particularly, this invention relates to the inventive construction, methods of preparation and use of a chemical-resistant, leak-proof, tamper-evident, self-sealing, integrally moulded closure for use in conjunction with containers employed predominantly in the chemical, food, and pharmaceutical industries.

BACKGROUND OF THE INVENTION AND DESCRIPTION OF RELATED ART

Advantages of plastic, majorly the ease of formability, lighter weight, ability to form thin-walled yet resilient structures, thermal and electrical insulating properties, appealing aesthetics, chemical inertness, ease of sterilization, decreased breakage, recyclability and lower costs as compared to glass, steel or other comparable materials have made them increasingly popular in the packaging industry. Prime examples of such plastics are virgin PET, PP, and HDPE which have been approved by the Food and Drug Administration authorities globally as being safe for use in contact with foodstuffs, chemicals, and pharmacological materials.

Closable containers designed for holding chemical, food, or pharmaceutical preparations are conventionally manufactured by blow-molding of discrete plastic performs, or injection moulding in preformed moulds, that result in a paired couple consisting of a container and it's mated but removable closure. The art abounds with examples of plastic bottles for aforementioned usages. Vials and tubes intended for use in laboratories for centrifugation, heating and freezing of sample fluids as well as dispensing valves are not difficult to envisage as an extension of such ambit.

Irrespective of the specific use-case, a protective and sanitary seal between the container and its closure is an extremely critical aspect while achieving their intended application. As can be readily appreciated, surfaces of the container and closure contacting each other may not provide a suitable barrier for limiting material, air and/or thermal leakage or risk of contamination. Hence, there is hence a pressing need to have some suitable means interposed between surfaces of the container and closure contacting each other for resulting in a releasable hermetic seal.

Prior art, to the extent surveyed, lists some scattered attempts to address the issues mentioned hereinabove. For example, plastic caps with pre-cut wads (in the shape and size of the cap) inserted in them illustrated in FIG. 1 are popular in the packaging industry. These caps need to be passed through an induction tunnel for induction sealing wherein electrical current causes wax layer on an aluminum foil seal to detach itself from the wad and cling onto neck of the container to made the seal. This is not an ideal solution however, as it introduces multiplicity of operations and child components appreciably because the closure essentially requires two-components to be independently arranged (wad+cap), and applied via additional operations of wadding, and induction sealing.

Induction sealing wads are designed for one-time use, hence the seal is not 100% recyclable. Besides increased production time and costs, the resultant product is can be easily copied or duplicated, does not provide a positive leak-tight seal once induction seal is removed (the user has to tear the seal at first time use, which cannot be reversed). Moreover, induction sealing process cannot be 100% guaranteed, and rejections do often result in large losses. Rejections can be due to less-than perfect induction seal, wad-delamination, off-center wad seating, weak seal due to uneven mouth surfaces etc. Lastly, major fire/explosion hazards do exist if passing solvent-based pesticides/bottles through an induction tunnel. It is therefore a pressing need to have some safe means that can substitute the need for having inductive sealing processes for achieving purpose-oriented containers employed predominantly in the chemical, food, and pharmaceutical industries.

Another example of prior art attempts to resolve the aforementioned issues are inner plugs made of plastic illustrated in FIG. 2 which are often used for containers directed towards storage of chemicals and pesticides. However, such plugs dimensioned for tight inner fit with mouth of the container need to be moulded separately in addition to a separate cap which is then screwed on the mouth of the container. This solution, though low cost, has same limitations as plastic caps with wad inserts, besides having very high risk of spillage (while pulling out the inner plug which is originally pushed in under high pressure), leakage (in case mouth dimensions are erroneous or inner mouth surface finish is not maintained). Therefore the need to have some safe means that can substitute the need for having inductive sealing processes for achieving purpose-oriented containers employed predominantly in the chemical, food, and pharmaceutical industries yet persists.

A third example that may be observed majorly in the cosmetic industry, is use of inbuilt plug caps in which the plug is a part of the cap and also made of the same material of the cap. Here, the plug ring helps to seal mouth of the container and provides leak-proof character. However, since the inner plug is made of the same material, most commonly PP or HDPE, as that of the cap, the seal between the mouth of the container and the cap is not hermetic, and hence the chances of leakage are very high. Leakages manifest even due to micro defects in the plug or the cap (fluids leak because of capillary action). Therefore, the need to have a better sealing closure which is not having deficiencies of background technologies yet persists. In these cases, a separate PE layer or a form layer is cut in dimensions of the annular region made in the cap by the inner plug ring. This form component is not an integral part of the cap. It needs to be placed in a separate manual step and when inserted, sits on the lip at the mouth of the container for ensuring leak proof character.

Another example is PE forms or rubber gaskets that are commonly used in an attempt to ensure leak-proof seal between caps and containers. However, such forms or gaskets are third party components and need to be moulded separately or cut to size in case of form layer and manually inserted for implementation. Often their materials are not chemically resistant and hence susceptible to deleterious effects when used in conjunction with strong or hazardous chemicals. Also, these forms or gaskets are not fixedly attached to the caps and can therefore fall off during transportation. This increases the operational overheads which are majorly counterproductive. Therefore the need to have some safe means that can substitute the need for having inductive sealing processes for achieving purpose-oriented containers employed predominantly in the chemical, food, and pharmaceutical industries yet persists.

As shall be appreciated in prior art closures available in the market today, the inner plug or induction seal is not a part of the cap and needs to be incorporated in a discrete step/procedure performed either before or after screwing on the cap. Thus for addressing the considerations mentioned hereinabove, it would be beneficial to have a unibody construction wherein the sealing member and cap are not separate and hence allow perfect seal, without mandating any separate step/procedure to be performed for inclusion either before or after screwing on the cap.

State-of-art therefore, does not list a single effective solution embracing all considerations mentioned hereinabove, thus preserving an acute necessity-to-invent for the present inventor/s who, as result of focused research, has come up with novel solutions for resolving all needs once and for all. Work of the presently named inventor/s, specifically directed against the technical problems recited hereinabove and currently part of the public domain including earlier filed patent applications, is neither expressly nor impliedly admitted as prior art against the present disclosures.

A better understanding of the objects, advantages, features, properties and relationships of the present invention will be obtained from the following detailed description which sets forth an illustrative yet-preferred embodiment.

OBJECTIVES OF THE PRESENT INVENTION

The present invention is identified in addressing at least all major deficiencies of art discussed in the foregoing section by effectively addressing the objectives stated under, of which:

It is a primary objective to provide a leak-proof closure, being a bottle cap, having an infallible but quick disconnect coupling when removably received in conjunction with means for holding chemical, food, or pharmaceutical preparations, particularly a container such as one among a bottle, vial, tube, jerry-can, or equivalent.

It is another objective to provide a leak-proof closure, being a cap, having an infallible but quick disconnect coupling when removably received in conjunction with means for dispensing, such as a valve, tube or equivalent.

It is another objective further to the aforesaid objective(s) that the closure so provided has a unibody construction, and the manner of its production does away with multiplicity of operations and child components otherwise involved in manufacturing closures of equivalent function.

It is another objective further to the aforesaid objective(s) that implementation of the closure so provided does away with induction sealing and therefore, the manual labour involved, electricity, shop-floor space, and time involved in induction sealing processes.

It is another objective further to the aforesaid objective(s) that the closure so provided exhibits positive indication of tampering readily discernable to eyes of the user.

It is another objective further to the aforesaid objective(s) that the closure so provided exhibits high chemical resistance or better, inertness, while helping to contain chemical, food, or pharmaceutical preparations.

It is another objective further to the aforesaid objective(s) that the closure so provided allows protective and sanitary seal yet does not introduce additional cost and process burdens on the packaging process.

It is another objective further to the aforesaid objective(s) that the closure so provided allows ready integration with conventional bottle neck designs.

It is another objective further to the aforesaid objective(s) that the closure so provided allows repeated and recyclable usage.

It is another objective further to the aforesaid objective(s) that the closure so provided that communication of air, heat, and/or materials is limited, or best avoided altogether, from in-between the contacting surfaces of said closure and the holding or dispensing means it is received with.

It is another objective further to the aforesaid objective(s) that the closure so provided allows undulations/unevenness of the bottle lip surface to be accommodated while providing a secure seal.

It is another objective further to the aforesaid objective(s) that the closure so provided cannot be easily copied or duplicated.

It is another objective further to the aforesaid objective(s) that the closure so provided allows safe and secure opening and closing the container or conduit the closure is received with.

It is another objective further to the aforesaid objective(s) that the closure so provided that it reduces a separate step of induction sealing or using inner plug fitting to containers, thereby streamlining and automating the packaging processes.

It is another objective further to the aforesaid objective(s) that the closure so provided allows usage with no additional skills or knowledge on part of the user.

It is another objective further to the aforesaid objective(s) that the closure so provided allows easy convenience for variance in aesthetics for resulting in mass appeal.

The manner in which the above objectives are achieved, together with other objects and advantages which will become subsequently apparent, reside in the detailed description set forth below in reference to the accompanying drawings and furthermore specifically outlined in the independent claims 1 and 10. Other advantageous embodiments of the invention are specified in the dependent claims.

BRIEF DESCRIPTION OF DRAWINGS

The present invention is explained herein under with reference to the following drawings, in which:

FIG. 1 illustrates a prior art plastic cap with wad inserted in it, and the bottle to which it is coupled having an induction seal.

FIG. 2 illustrates a prior art inner plug made of plastic and the container to which it is received.

FIG. 3 (a) and (b) illustrate a schematic cross-sectional view and bottom side perspective view respectively of the CRTESS cap made according to the disclosures hereof.

FIG. 4 (a) and (b) are schematic illustrations of the CRTESS cap in use in conjunction with a jerry-can and bottle respectively, particularly identifying therein the tamper-evident ring provided according to the disclosures hereof.

FIG. 5 (a) to (d) are top view, isometric view, side view, front view, and bottom views respectively of the CRTESS cap made according to the disclosures hereof.

FIG. 6 is a schematic cross-sectional view of the functional seal achieved by the CRTESS cap according to the disclosures hereof.

FIG. 7 (a) to (c) are side view, top view, and isometric view of one embodiment hereof, being the 61 mm CRTESS CAP with provision in cap for vent plug.

FIG. 8 (a) to (c) are side view, top view, and isometric view of another embodiment hereof, being the CRTESS CAP with racket type tamper-evidence.

FIG. 9 (a) to (c) are side view, top view, and isometric view of another embodiment hereof, being the CRTESS CAP with sealing layer around annular space of the cap.

The above drawings are illustrative of particular examples of the present invention but are not intended to limit the scope thereof. The drawings are not to scale (unless so stated) and are intended for use solely in conjunction with their explanations in the following detailed description.

In above drawings, wherever possible, the following same references and symbols have been used throughout to refer to the same or similar parts—

-   (01)—CRTESS cap -   (02)—Outer shell -   (03)—Inner plug ring -   (04)—Lip of bottle (05) -   (05)—Bottle -   (06)—Knurling -   (07)—Thread on neck (08) -   (08)—Externally threaded neck of bottle (05) -   (09)—Tamper-evident ring -   (10)—Vent plug

Though numbering has been introduced to demarcate reference to specific components in relation to such references being made in different sections of this specification, all components are not shown or numbered in each drawing to avoid obscuring the invention proposed.

SUMMARY OF THE INVENTION

In a preferred embodiment disclosed hereof, there is provided an inventive integrally moulded plastic plug ring cap for sealing a container having an externally threaded neck thereon. Also disclosed is a method for forming said cap. The present inventor proposes to address at least majority of the shortcomings of state-of-art by advantageous implementation of a bi-injection moulding process wherein discrete thermoplastics are moulded sequentially for resulting correspondingly into a soft inner lip. Outer hard cap/shell is optionally provisioned with external knurling for better grip and to be compatible with automatic capping machines. Usage of the closure proposed herein is of screw fit type for quick disconnect coupling with the container/conduit at which said closure is intended to be received. Process involved does away with more complex, costly, and time-consuming induction sealing practiced traditionally. Resulting article is a integrally moulded plastic plug ring cap capable of providing a guaranteed, reversible hermetic seal when received at the mouth of means for holding or conveying chemical, food, and pharmaceutical preparations.

Attention of the reader is now requested to the detailed description to follow which narrates a preferred embodiment of the present invention and such other ways in which principles of the invention may be employed without parting from the essence of the invention claimed herein.

DETAILED DESCRIPTION

Principally, general purpose of the present invention is to assess disabilities and shortcomings inherent to known systems comprising state of the art and develop new systems incorporating all available advantages of known art and none of its disadvantages.

Before undertaking the detailed description of the invention below, it may be advantageous to set forth definitions of certain words or phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect, with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “CRTESS cap” shall mean Chemical-Resistant Tamper-Evident Self-Sealing cap which is the integrally moulded plastic plug ring cap proposed in the present invention; “PET” shall mean Poly-Ethylene Terephthalate; “HDPE” shall mean High-density polyethylene; “PP” shall mean polypropylene; “PE” shall mean polyethylene; “means for holding or conveying chemical, food, and pharmaceutical preparations” shall refer any one among a bottle, vial, tube, jerry-can, conduit, tube or equivalent which additionally are intended to be synonymous in this paper without affecting essence of the invention.

The present invention primarily focuses on avoiding, or at least minimizing the issues recited in the background section of this paper. Accordingly, the disclosures herein are directed towards the inventive construction, methods of preparation and use of a leak-proof closure, being the CRTESS cap, having an infallible but quick disconnect coupling when removably received in conjunction with means for holding chemical, food, or pharmaceutical preparations, particularly a container having an externally threaded neck such as one among a bottle, vial, tube or equivalent. Further embodiments of the present invention are directed to a corollary aspect, being a leak-proof closure, being a cap, having an infallible but quick disconnect coupling when removably received in conjunction with means for dispensing, such as a valve, tube or equivalent.

According to a first aspect of the present invention as depicted in the accompanying FIGS. 3(a) and 3(b), construction of the CRTESS cap (01) includes a plastic outer shell (02) of cylindrical geometry that provides strength and rigidity, and a chemically resistant inner plug ring (03) that provides leak-proof character to the CRTESS cap (01). The outer shell (02) is composed of a flat circular top having a circumferentially-continuous, internally-threaded side wall descending at a right angle from said flat circular top to end in an open mouth to be received on the externally threaded neck of the container for sealing the same.

According to one aspect of the present invention, inner sealing layer, that is the inner plug ring (03) is of chemically resistant soft material (flexible sealing material which is moldable and compatible with PE materials for adhesion while injection moulding) which helps in effective sealing against lip (04) of mouth of the bottle (05) at which said CRTESS cap (01) is to be received. In a related aspect, the inner plug ring (03) is moulded to assume an annular geometry and arranged to descend concentrically from underbelly of the flat circular top of the outer shell to an extent (height, thickness, conicity, etc) sufficient to allow force-fitting onto the externally threaded neck of the container when the cap is screwed home thereon.

According to another related aspect of the present invention, the soft material of the inner plug ring (03) ensures that undulations/unevenness in surface of the bottle lip (04) to be accommodated while providing a secure seal. This in turn, ensures that passage of air, heat, and/or materials in-between the CRTESS cap (01) and the bottle (05) at which it is received is nil, or at least limited to insignificant levels. Therefore, the CRTESS cap (01) has infallible leak-proof character when removably received in conjunction with means for holding chemical, food, or pharmaceutical preparations.

According to another related aspect of the present invention, tamper-evident means continuous with mouth of the outer shell (02) are included for positive indication of tampering readily discernable to eyes of the user. Said tamper-evident means being composed of two initially joined, but separable members, such as a perforated tear-type or ratchet-type ring, of which one member is attached at open end of the outer shell (02) and the other member fixedly embraces the externally threaded neck (08) of the container

According to another aspect of the present invention explained with combined reference to the accompanying FIG. 3(a), FIG. 3(b) and FIG. 4, the CRTESS cap (01) optionally is made to have knurling (06) on its external surface for aesthetics as well as for the CRTESS cap (01) to be used in conjunction with an automatic capping machine. Internal surface of the outer shell (02) has a thread for screw fit onto matching thread (07) on neck (08) of the bottle (05). Mouth of bottle (05) sits in the annular area made in the CRTESS cap (01) by the inner plug ring (03).

According to another aspect of the present invention explained with reference to the accompanying FIG. 4, the CRTESS cap (01) further includes a tamper-evident ring (09) that sits around neck (06) of the bottle (07). The tamper-evident ring (09) is designed to be broken off and remains on the bottle (05) when the CRTESS cap (01) is removed from the bottle (05) for the first time, thereby giving an immediate positive indication of tampering readily discernable to eyes of the user. For such effect, it is critical that diameter and profile of the locking ring (10) that sits around neck (08) of the bottle (05) has to be maintained within tolerance.

According to a second aspect of the present invention it would be necessary to consider the process for preparing the CRTESS cap (01) subject hereof. In a preferred arrangement, the CRTESS cap (01) is prepared via a bi-injection moulding process wherein the inner plug ring (03) is molded first, and followed by molding of the outer shell (02). This ensures that the resulting product, that is the CRTESS cap (01), has a one piece construction being achieved via a simplistic process and thereby does away with multiplicity of operations and child components otherwise involved in manufacturing prior art closures of equivalent function.

It shall be appreciated from the preceding paragraph, that induction sealing is entirely avoided in the process for preparing the CRTESS cap (01) proposed herein. Also, no separate PE layer or rubber gasket or a form layer is needed to ensure leak-proof character. In fact, sealing is totally provided by the integral sealing layered construction recited hereabove. Therefore, manual labour involved, electricity, shop-floor space, and time involved in said induction sealing step is entirely avoided.

Implementation of the present invention is intended to encompass various embodiments, among which a few are explained below with reference to certain examples that illustrate generically the manner in which principles of the present invention may be employed.

EXAMPLE 1: PROTOCOL FOR PRODUCTION OF THE CRTESS CAP

As mentioned in the foregoing disclosures, the CRTESS cap (01) proposed herein is prepared via a bi-injection moulding process wherein the inner plug ring (03) is molded first, and followed by molding of the outer shell (02).

According to one feature of the present invention evident from Example 1 above, the inner plug ring (03) is fused with the outer cap (02) during the molding process itself, hence the resulting CRTESS cap (01) has a single component/unibody construction. Hence no problems are experienced as otherwise such as wads jumping out of the caps or being displaced out of position observed in prior art solutions. FIG. 5 (a) to (d) are top view, isometric view, side view, front view, and bottom views respectively of the final product, that is the CRTESS cap (01) made according to the disclosures hereof.

In a preferred embodiment, a plastic HPDE cap is maintained during moulding at an increased temperature and sealing area is injected under high temperature and pressure conditions with a chemically-resistant material to form the inner plug ring. Formable material of the inner plug ring is selected to be one having less rigidity than that of the outer shell. High temperatures cause the sealing area to fuse into a single component. The sealing portion is moulded to form a skirt, therein forming the walls and horizontal area beneath the cap. This imparts a very distinct advantage to the cap by providing a very good sealing around the mouth of the bottle as depicted in the accompanying FIG. 6. Consequently, the sealing portion engages with the bottle neck and provides 100% leak-proof character every time the cap is closed.

EXAMPLE 2: TESTING OF THE CRTESS CAP

-   -   a) Drop test: The CRTESS cap made using the protocol of Example         1 was received via screw fit at mouth of a liquid filled bottle.         Said bottle with CRTESS cap was dropped from various heights.         Here, it was observed that the bottle with CRTESS cap neither         ruptures nor leakage was observed from the bottle. This         concludes that the CRTESS cap successfully cleared the standard         drop test applicable for articles of its nature.     -   b) Leakage test: The CRTESS cap made using the protocol of         Example 1 was received via screw fit at mouth of a liquid filled         bottle. Said bottle with CRTESS cap was subjected to an air         pressure of 20 kPa for 5 min. Here, it was observed that the         bottle with CRTESS cap neither ruptures nor leakage was observed         from the bottle or said cap. This concludes that the CRTESS cap         successfully cleared the standard leakage test applicable for         articles of its nature.     -   c) Hydraulic test: The CRTESS cap made using the protocol of         Example 1 was received via screw fit at mouth of a liquid filled         bottle. Said bottle was subjected for a period of 30 minutes to         a hydraulic gauge pressure of 100 kPa. Here, it was observed         that the bottle with CRTESS cap neither ruptures nor leakage was         observed from the bottle or said cap. This concludes that the         CRTESS cap successfully cleared the standard hydraulic test         applicable for articles of its nature.     -   d) Stacking test: The CRTESS cap made using the protocol of         Example 1 was received via screw fit at mouth of a liquid filled         bottle. A superimposed weight was placed on top of a plywood         sheet placed on the top of said bottle for a period of 24 hours.         The weight was equivalent to stack height of 3.0 m. Here, it was         observed that the bottle with CRTESS cap neither ruptures nor         leakage was observed from the bottle or said cap. This concludes         that the CRTESS cap successfully cleared the standard stacking         test applicable for articles of its nature.

EXAMPLE 3: ALTERNATIVE VARIANTS OF THE CRTESS CAP

The CRTESS cap proposed herein may be produced in alternative versions depending on the specific use-case and application intended. The following versions are few non-limiting examples in this line-a)

-   -   a) CRTESS Cap with a vent plug insertion option and         self-sealing: As seen in the accompanying FIG. 7 (a) to (c),         provision is made in the CRTESS cap itself to insert a vent plug         (011). The vent plugs are third party sourced components         comprising a plastic plug with a membrane inside. The membrane         doesn't allow liquid to pass only air to pass. Hence any         pressure difference which occurs inside the container is solved         by the vent plug. In this variant of the CRTESS cap, the         inventor named herein has made a provision such that the vent         plug can be directly inserted into the CRTESS cap (this is         unconventional as usually such vent plugs are inserted into the         inner plug or comes as a part of the sealing wad)     -   b) CRTESS Cap with complete top seal sealing and racket type         tamper-evidence ring: As seen in the accompanying FIG. 8 (a) to         (c), this variant is identified in including a racket type         tamper-evidence ring in conjunction with the CRTESS cap. Top of         the CRTESS cap is also provided with sealing layer.     -   c) CRTESS Cap where sealing is at only the annular region of the         cap: As seen in the accompanying FIG. 9 (a) to (c), this variant         is identified in including the sealing layer around the annular         space of the CRTESS Cap. Here, the sealing layer doesn't cover         the entire top area of the CRTESS Cap but it is injected in the         middle area to thereby the material to flow to the annular plug         ring area. Sealing is thus provided at the annular region area.

The CRTESS cap proposed herein can be used on a large scale across all bottles with 46 mm and 61 mm neck diameters. However nothing said in this paper shall prohibit scaling up or down, or assuming an alternative profile of the cap, for suiting different neck sizes and profiles of any of presently available or future means holding or conveying any among holding chemical, food, or pharmaceutical preparations.

As may be appreciated from the foregoing disclosures, the present invention encompasses the production and use of able caps, covers or seals for protecting means for holding or dispensing chemical, food, and pharmaceutical preparations. As such, the present invention is identified in having the following salient features—

-   -   1) CRTESS cap is a truly single component solution     -   2) Inner plug ring of the CRTESS cap chemically resistant and         thus can be safely used in association with means holding or         conveying any among holding chemical, food, or pharmaceutical         preparations.     -   3) CRTESS cap can be used just like any other cap by the user     -   4) CRTESS cap can be screwed on using a capping machine     -   5) CRTESS cap can be screwed on and off any number of times,         thereby allowing repeated usability and recyclability     -   6) Process of induction sealing and its associated vices are         done away completely in production of the CRTESS cap     -   7) Need of separate wads is omitted as induction sealing         operation is avoided     -   8) Due to bi-injection moulding process, the outer cap and inner         plug ring can be provided in different colors, thereby affording         greater choice for aesthetics besides being an         anti-counterfeiting measure or to validate the authenticity of         any product sold in the market (color of inner plug ring is only         known to the bonafide manufacturer, and can be varied from batch         to batch. Any discrepancy therefore will automatically count as         a counterfeit article).     -   9) Presence of tamper-evident ring allows positive indication of         tampering readily discernable to eyes of the user.     -   10) Production protocol is not easily replicable, therefore         preventing spurious distributors and manufacturers from         introducing duplicates of the the CRTESS cap, thereby increasing         assurance of genuineness in minds of users.

As will be realized further, the present invention is capable of various other embodiments and that its several components and related details are capable of various alterations, all without departing from the basic concept of the present invention. Accordingly, the foregoing description will be regarded as illustrative in nature and not as restrictive in any form whatsoever. Modifications and variations of the system and apparatus described herein will be obvious to those skilled in the art. Such modifications and variations are intended to come within ambit of the present invention, which is limited only by the appended claims.

It shall be generally noted that at least a major portion of the foregoing disclosures of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in files or records of the receiving Patent Office(s), but otherwise reserves all copyright rights whatsoever. 

I claim: 1) A cap for sealing a container having an externally threaded neck thereon, comprising— a) An outer shell of formable material moulded to assume a cylindrical geometry, said outer shell being composed of a flat circular top having a circumferentially-continuous, internally-threaded side wall descending at a right angle from said flat circular top to end in an open mouth to be received on the externally threaded neck of the container for sealing the same; b) An inner plug ring of a formable material moulded to assume an annular geometry and arranged to descend concentrically from underbelly of the flat circular top of the outer shell to an extent sufficient to allow force-fitting onto the externally threaded neck of the container when the cap is screwed home thereon; and c) A tamper-evident means continuous with mouth of the outer shell, said ring being composed of two initially joined, but separable members of which one member is attached at open end of the outer shell and the other member fixedly embraces the externally threaded neck of the container Characterized in that— i) The formable material of the inner plug ring is selected to be one having less rigidity than that of the outer shell to allow a tight fit and therein accommodating any undulations on lip of the externally threaded neck; ii) The formable material of the inner plug ring is selected to be one having high chemical resistivity to allow inert behavior upon contact with contents of the container; and iii) The outer shell and inner sealing plug ring are integrally moulded together, thereby allowing a leak-proof seal when the cap is received onto the container. 2) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 1, wherein the container is an article for storing or conveying fluids, said article being chosen among a bottle, vial, tube, jerry-can, conduit, tube or equivalent. 3) The cap for sealing a container having an externally threaded neck thereon as claimed in claims 1 and 2, wherein the cap is a screw-type cap allowing a screw-type fit when received rotatably on the threaded neck of the container. 4) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 1, further including an aperture passing through the flat circular top of the outer shell for receiving a vent plug. 5) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 4, wherein the vent plug is a plastic plug with a membrane inside that allows gases, but not liquids, to selectively pass through therein allowing breathability to contents of the container when sealed using the cap. 6) The cap for sealing a container having an externally threaded neck thereon as claimed in claims 1 and 3, wherein threading on the inner wall of the outer shell and neck of the container have a complementary pitch to thereby allow the cap to assume a sealed, leak-proof fit when received rotatably on the threaded neck of the container. 7) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 1, wherein the tamper-evident means are selected among a perforated-type and racket type tamper-evidence rings. 8) The cap for sealing a container having an externally threaded neck thereon as claimed in claim 1, wherein the formable material of the outer shell is selected among the group of thermoplastics including polyethylene, High-density polyethylene, and polypropylene. 9) The cap for sealing a container having an externally threaded neck thereon as claimed in claims 1 and 8, wherein the formable material of the inner plug ring is selected among flexible sealing materials, a compounded polypropylene thermoplastic in particular, which are compatible with the formable material of the outer shell for adhesion there-with while undergoing injection moulding. 10) A method for production of the cap recited at claim 1, comprising— a) Moulding of formable material at an increased temperature to obtain an outer shell of cylindrical geometry, said outer shell being composed of a flat circular top having a circumferentially-continuous, internally-threaded side wall descending at a right angle from said flat circular top to end in an open mouth to be received on the externally threaded neck of the container for sealing the same; and b) Maintaining the outer shell obtained at step a) at high temperature while moulding of an inner plug ring in form of a skirt integral to the outer shell by injecting the sealing area of the outer shell under high temperature and pressure conditions with a formable material less rigid than that of the outer shell, therein causing the outer shell and inner plug ring to fuse into a unibody construct. 